The theory of evolution has been around since the 1800s and is widely accepted around the world. Evolution by natural selection is one of the best-substantiated theories in the history of science, supported by evidence from a wide variety of scientific disciplines, including paleontology, geology, genetics and developmental biology. Still, there are many people who hold religious explanations for the origins and growth of life. Some take a literal reading of scripture (called Young Earth Creationists) while others use more complex, pseudo-science (Intelligent Design). If you find yourself in a debate, be sure to anticipate these groups’ claims. Try to reconcile religious arguments while defending the science behind evolution.

Steps

Method1

Reconciling Religious Claims

1

Separate faith and science. Science tries to understand the natural world and how it works. Think of it as a method of inquiry, one that measures and gathers evidence in support of or against hypotheses. But science as it stands has no way to determine whether or not a deity exists. It can’t make a judgment on the issue.[1] Make this key distinction, or you’ll get nowhere.

Point out that evolution tries to explain the growth of life on earth. It has nothing to say about the origins of life or the universe. Arguments like “something can't come from nothing” aren't relevant to the question at hand.

The central idea of biological evolution is that all life on Earth shares a common ancestor, just as you and your cousins share a common grandmother. Through the process of descent with modification, the common ancestor of life on Earth gave rise to the fantastic diversity that we see documented in the fossil record and around us today. Evolution means that we're all distant cousins: humans and oak trees, hummingbirds and whales.

Accept and ask the other person to accept that one of you is talking about science, which is supported by empirical evidence, while the other is talking about faith and non-science.

2

Acknowledge evolution’s limits. Both creationism and evolution are worldviews. They proceed from a certain account of the world’s origins and assume the world conforms to this account. In other words, the conclusion is already held to be true. Recognize that this worldview limits you, just as your friend’s worldview limits her.[2]

Be able to admit that you can’t disprove the existence of deities or with evolutionary theory, just as your friend can’t disprove evolution with arguments from faith. However you can debunk falsifiable hypotheses, including creation myths and if there was valid evidence against the theory of evolution, it would be accepted by the scientific community.

No one really knows the origins of the universe or where we came from. Make a goodwill effort to see things from the creationist point of view.

Don’t be afraid to admit that science cannot explain everything about the origin of life. At the same time, what we don’t know now may well be discovered in the future.

3

Point to other creation myths. Point out that most religious traditions have creation myths. The Judeo-Christian story from the Bible is not unique, but has parallels in Babylonian texts like the Enuma Elish (i.e., in the beginning, there was only undifferentiated water swirling in chaos). Many other religious traditions have their own stories, as well.[3]

The ancient Persians believed that the universe was created in a six or seven part series. First the sky, then water, the earth, plants and animals, and humans. Fire was the last creation.[4]

The ancient Greeks told the story of Gaia, the earth, who gave birth to the heavens, mountains, and sea. She later gave birth to the world-ocean and other primordial races.[5]

The Yoruba people say that, before the earth, the god Olorun lived with divine entities called orisha around a great baobab tree in the sky.

4

Accept that evolution and God do not have to be contradictory. People like to argue that science and religion, or faith and reason, are mutually exclusive. This is not so. The fact is that science is agnostic about God – it has nothing to say about a divine creator. This means that it is possible to believe in evolution AND in a divinely created universe.

Many religious people reject naturalistic evolution because they think it denies God’s role in the universe, especially in creation and providence (i.e., the idea that God actively intervenes on earth).

Evolution may contradict a literal reading of the Bible. But, people have read the Bible in other ways for centuries and many Christians accept the story as a myth or allegory, not the literal truth.

Point out that religious figures like Pope Francis believe in evolution, and say that evolution is not only compatible with a Creator but requires it.[6]

Method2

Defending Science

1

Familiarize yourself with creationist claims and how to refute them. Young Earth Creationists raise some common objections, which are fairly easy to handle. Be ready for these and offer honest, straightforward answers.[7]

Some objections are philosophical or ethical, i.e. evolution is atheistic or immoral, evolution means life has no meaning, natural selection is might equals right, or even evolution itself is a religion.

Don’t feel the need to reply to these claims. As said above, they are moral rather than scientific issues.

More sophisticated creationists will try to undercut the science or scientific consensus behind evolution. I.e., evolution is only a theory, evolution hasn’t been proved, there are gaps in the fossil record, mutations are harmful, or evolution violates the second law of thermodynamics.

2

Urge your friend to understand the philosophy of science. Try to make sure he can explain the scientific method and what “theory” means. Science builds its theories to fit observed facts. It is theoretical and open to revision, as fact dictates. This does not mean that it’s unsupported by evidence.[8]

Dispel misconceptions about the word “theory.” A theory is an idea that is supported by evidence, whereas a hypothesis is a proposition to be tested. While theories like evolution, plate tectonics, and relativity are open to revision, they are supported by vast amounts of evidence.[9]

A good scientist will reject or revise evolutionary theory based on the facts that are presented. In fact, evolutionary theory has been revised many times and will continue to be tweaked in the future.

If you must, explain that revision is not a weakness but an example of the scientific process at work. Scientists take almost nothing for granted and are ready to change their minds when new information is discovered.

Impress that there is, in fact, near total consensus in the scientific community. Evolution is accepted by 99% of biologists.[10].

3

Reiterate that evolution is sound science. Some creationists claim that the theory of evolution is not sound for two reasons: it is not testable or falsifiable. It makes claims about things that were not actually observed and cannot be recreated. Be patient and make your case.[11]

This claim does not account for the difference between micro- and macro-evolutionary theory, i.e. changes in species over time and changes in groups above the level of species.

Scientists have plenty of observed evidence for evolution on the micro level, with studies of fruit flies, cells, and Darwin’s study of Galapagos island finches, for example.

On the macro level, it is true that we can’t test past conditions. But we can study physical evidence like the fossil record and make informed inferences. We would expect humans to have evolved from a series of earlier hominids, for example, and this what fossils show. We do not find hominids in dinosaur-era strata.

The idea that evolution can’t be falsified isn’t true. It could easily be falsified if we found evidence for, say, a static fossil record or the spontaneous generation of a species.

4

Calmly and clearly rebut other claims. Young Earth Creationists have a whole supply of pseudo-scientific arguments. Be prepared for false claims having to do with mutation, fossils, genetics, and entropy. Reply patiently, but realize that you may never actually convince your friend.[12][13]

Challenge doubts about natural selection. Do children look like their parents? Do they inherit traits genetically? And can we notice any trends over time - for example, people's feet are bigger today than they were 200 years ago.

What about animals? Animals and people inherit different colored skin, hair/fur, and dimensions from their ancestors. These differences can be advantageous (for example, a giraffe with a longer neck can eat more leaves, be healthier, live longer, and reproduce more.)

Some creationists will points out gaps in the fossil record – where are the “transitional” species we should see with evolution? In fact, there are many transitional fossils. Point to Archeopteryx: still a dinosaur, but with light bones and feathers. Most people know that it has birdlike features, so point out that it has many more that are fully reptilian.[14]

Some also say natural selection can´t explain different species. But animals move to different places with different conditions. A good example is the Darwin finches, which had the same origin but evolved on different islands. They have different beaks and are biologically distinct species.

One thorny claim is about entropy, the idea that systems tends toward disorder. How can we account for complex life in an entropic universe? This is actually a misunderstanding. The Second Law of Thermodynamics only says that the whole entropy of a system can’t decrease. Local complexity does not contradict the law. Otherwise, things like mineral crystals and snowflakes would be impossible.[15]

Method3

Dealing with Intelligent Design

1

Note that Intelligent Design (ID) is not science. Recently many deniers have attacked evolution with a pseudo-scientific theory called “Intelligent Design.” This is the idea that the physical and biological systems in the universe must come from the ‘’’purposeful design’’’ of a creator. It’s more complex than Young Earth Creationism, but it’s no more scientific.[16]

In a nutshell, ID states that the universe is really complex and has things that are well-suited to their observed function. Think the human eye. This functionality and complexity can’t be chance, it states. It must be the work of a designer, i.e. God.

Many supporters of ID also accept microevolution, i.e. the idea of development in existing species.

Sound good? Not so fast. Scientific theory has to have evidence that excludes all other possibilities. It also needs to make predictions that can be tested and confirmed or denied.

The problem is that ID can’t be empirically tested. It also doesn’t exclude other explanations: biologists have shown that complex things, like blood clotting, for example, could have developed from earlier, simpler systems.[17]

ID fails to predict new things, as well. This is something scientific concepts should do.

2

Undercut claims about complexity and function. ID doesn’t deny that life forms in the universe can progress from simple to more complex states. But it quibbles. Its supporters argue that the ‘’’fact’’’ of evolution could not have occurred only through natural processes. They point to the complexity and patterns we see in nature, and also to how animals are well-adapted to environments.[18]

As said, evolution is an alternative explanation for complexity. ID can’t disprove this, and it has no way of testing its own claims.

ID also claims that functionality proves the hand of a creator – that a creator designed animals to be well-adapted. However, evolution also explains function. Be sure to point this out.

Functionality does not have to come from design. In fact, scientists argue that evolution is blind. Species that survive are not perfectly adapted but “good enough,” and live long enough to reproduce.

Use the example of dinosaurs. Why would a designer have to create so many species that went extinct? What was the purpose of these animals?

3

Deal with the argument from chance. Supporters of ID like to argue that the evolution of complex forms is improbable. It is unbelievable that life could arise all by itself, because the odds are so small. What are the chances of a working car emerging from a “junkyard tornado”? Slim to none. Therefore, they point to an intelligent plan. This argument is also not very good.[19]

The “junkyard tornado” is not a sound analogy with life. Supporters of ID ignore the fact that there are laws of interaction in the universe, natural forces acting between particles, and other considerations.

Point out that the odds are not stacked against the natural origin of life (abiogenesis). The probability of the simplest building block forming is about 1 in 10 to the 40th power. This is a huge number. But billions of trials would happened at every moment on primordial earth.[20]

Cite the infinite monkey theorem. Say a monkey or group of monkeys are randomly mashing keyboards. The odds that they will type something comprehensible are near zero at any one moment. BUT, if with enough time or enough monkeys the long-term odds are near certain.[21] The odds for abiogenesis are similar.

4

Attack ID’s central logical problem. ID is based on a key flaw: the idea of a designer, or that design requires a designer. This is a logical fallacy, one you should point out to your friend.[22]

Poke holes in the assumptions. ID relates complexity and pattern with intelligence, for one thing. We look at things around us – chairs, cars, computers – and assume they have a designer.

Shouldn’t we suppose other complex things in the universe need a designer? Actually, no. This is a “fallacy of incredulity”: you assume something did not happen because you can’t understand how it could happen.

Point out slippery definitions, too. ID confuses the meaning of the word “design.” Design can mean (1) a structure or pattern that is functional, stable, or seen as beautiful or (2) the act of purposefully making such a structure. Note that “design” in the first sense can, in fact, arise accidentally or randomly.

Tips

In modern times, the term evolution is widely used, but the terms evolutionism and evolutionist are seldom used in the scientific community to refer to the biological discipline as the term is considered both redundant and anachronistic, though it has been used by creationists in discussing the creation-evolution controversy.